1. Field of the Invention
This invention relates to processes and intermediates for preparing 1H-imidazo[4,5-c]quinolines. In another aspect this invention relates to processes and intermediates for preparing 1-substituted-1H-imidazo[4,5-c]quinolin-4-amines.
2. Description of the Related Art
The synthesis of 1H-imidazo[4,5-c]quinolin-4-amines has been described in U.S. Pat. Nos. 4,689,338 (Gerster) and U.S. Pat. No. 4,929,624 (Gerster et al.). The methods described therein involve the step of heating the 4-chloro compound in the presence of ammonium hydroxide or ammonia under pressure (e.g., in a sealed reactor) to afford the 4-amino compound.
The reaction of phenyl isocyanate with heteroaromatic 6-memberd ring N-oxides has been reported in "Organic Chemistry: A series of Monographs, Chemistry of the Heterocyclic N-oxides." A. R. Katritsky and J. Kagowski. Alfred T. Bloomquist, Ed., Academic Press, 1971. The reaction is said to afford the .alpha.-anilino derivative.